ABC effect: A signal of a quasibound Δ Δ system

M. Bashkanov, H. Clement*, E. Doroshkevich, O. Khakimova, F. Kren, A. Pricking, T. Skorodko, G. J. Wagner

*Corresponding author for this work

Research output: Contribution to journalShort surveypeer-review


The first exclusive measurements at CELSIUS-WASA for the double-pionic fusion to d or 3He reveal the ABC effect-a low-mass enhancement in the π π invariant mass spectrum-to be a σ channel phenomenon associated with the formation of a Δ Δ system and combined with a resonance-like behavior in the total cross section. This quasibound system with a mass below the Δ Δ threshold obviously survives also in nuclei as a resonance configuration producing the ABC effect there.

Original languageEnglish
Pages (from-to)304-305
Number of pages2
JournalProgress in Particle and Nuclear Physics
Issue number1
Publication statusPublished - 1 Jul 2008


  • Δ Δ system
  • ABC effect
  • Isoscalar
  • p n system
  • Resonance

Cite this